Automatic gunsight



BEU MSE' p 1959 s. L. ST. PALLEY AUTOMATIC GUNSIGHT Filed Nov. 7, 1958 STEPHEN L. SIPALLEY INVENTOR.

United States Patent AUTOMATIC GUNSIGHT Stephen L. St. Palley, Dalton, Mass.

Application November 7, 1958, Serial No. 772,553

2 Claims. (Cl. 88--2.2)

This invention relates to gun sights and is a continuation in part of my prior application Serial No. 689,349 filed on October 10, 1957, now abandoned.

it is known that the gravitational drop of a missile shot out from a gun increases rapidly with the distance traveled by the missile, so that the farther the target is the greater the angular elevation of the barrel of the gun must be to hit the target. The customary method of compensation for the gravitational drop of the trajectory is to employ a sighting device which is angularly adjustable with respect to the barrel and the usual practice is to adjust the angle of the sighting device so that the vertical drop from the axis of the barrel to the line of sight, measured at the target, is equal to the gravitational drop of the trajectory at that point. This method obviously requires the adjusting of the gun sight every time the target distance is changed which, under some conditions common in military application and in hunting, is not possible due to lack of time for making the adjustment.

The principal object of my invention is to provide a gun sight which, by the simple action of the sighting of the target, will automatically position the barrel of the gun so as to compensate for the gravitational drop of the trajectory at widely varying target distances without the need of making any adjustment on the gun sight, thereby making possible the rapid and accurate aiming of the gun at rapidly varying target distances.

Another important object of my invention is to provide a gun sight which is firmly attached to the gun barrel, without the customary angular adjustment and locking mechanism, thereby offering a construction of great simplicity and manufacturing simplicity.

A further object of my invention is to provide a gun sight which can be easily adapted to guns of all types having widely varying missile velocities and effective target ranges.

Other objects and advantages of my invention will be apparent during the course of the following description.

In the accompanying drawing, forming a part of this application, wherein for the purpose of illustration is shown a preferred form of my invention.

Figure 1 is a sectional view of the optical unit and the cross hair panel employed in the preferred form of my gun sight,

Figure 2 is a rear elevational view of the optical unit,

Figure 3 is a rear elevational view of the cross hair panel,

Figure 4 is a longitudinal sectional view of my gun sight mounted on the gun barrel.

Referring to the drawing, the numeral 1 designates the optical unit of my gun sight, which may be made of prastics, glass, or other suitable transparent material.

iIn the preferred form, shown in Fig. 1 and 2, this optical unit 1 is cylindrical in shape, with a geometric axis 5, and has a convex spherical front surface 2, and a concave spherical rear surface 3. Passing through the centers of these spherical surfaces 2 and 3, is the optical axis 4, a

"ice

straight line which, in this form, is parallel to said geometric axis 5, and is disposed in the same vertical plane.

The optical characteristics which make the advantageous and novel operation of my gun sight possible, are obtained by the special dimensioning of the optical unit 1.

In the design of convex-concave lenses it is known that by the use of the Steinhall Cone formula it is possible to coordinate the curvatures of the spherical convex and concave surfaces and the axial thickness of the lens so as to obtain predetermined positive or negative dioptric values. The lenses thus dimensioned have prismatic power; they will deflect the ray of light, toward the optical axis in case of positive dioptric value, and away from the optical axis in case of negative dioptric value. These lenses possess the important characteristic, utilized in the present invention, that the angle of deflection of the light ray in these lenses vary with the decentration of the light ray measured from the optical axis of the lens.

In order to measure the decentration of the light ray, the concave rear surface 3 of the lens is provided with a vertical hair line 6, passing through the optical axis 4 and through the geometric axis 5, and with horizontal hair lines 7, 8, and 9, disposed at various predetermined decentrations from the optical axis 4, as illustrated in Fig. 2. Disposed coaxially at some distance from the rear surface 3 of the lens is the cross hair panel 10 (see Figs. 1 and 3) which has a similar vertical hair line 16 intersecting the optical axis 4 and the geometric axis 5, and horizontal hair lines 17, 18, and 19 located at the same decentrations as the corresponding horizontal hair lines on the rear surface 3 of the lens.

In Fig. 1 the dotted lines represent aiming light rays passing through the vertical hairlines 16 and 6 (see Figs. 2 and 3) at different decentrations. The light ray passing through the horizontal hairlines 17 and 7 will enter the optical unit 1 and will be deflected. In the example illustrated the optical unit 1 is so designed as to have a positive dioptric value, therefore, the aiming light ray 17, 7 will be deflected toward the optical axis 4, at an angle of deflection determined by the decentration of this 17, 7 light ray from the optical axis 4. Similarly, the light ray passing through 18 and 3 (see Fig. 1) will also be deflected toward the optical axis 4, but at a greater angle due to its greater decentration. The light ray through 19 and 9, being the farthest away from the optical axis 4, will have a still greater angle of deflection. It is characteristic in my invention that the aiming light ray is varied in decentration, but its direction between the optical unit 1 and the cross hair panel 10 is always parallel to the optical axis, also, that the angle between the optical axis and the deflected aiming light ray increases with the decentration of the light ray.

Fig. 4 illustrates the assembled gun sight mounted on the barrel. The optical unit 1 and the cross hair panel 10 are enclosed in a sight tube 11, which is secured to the gun barrel 13 by the rigid connection 12, so that the optical axis 4 and the geometric axis 5 of the gun sight are strictly parallel to the axis of the bore of the barrel, designated by 14. The arrow adjacent to the axis 14 indicates the direction of the travel of the missile in the barrel 13. Thus in the mounted gun sight the optical unit 1 is disposed toward the target, and the cross hair panel 10 toward the eye of the operator.

The operation of my gunsight is as follows:

The operation of my gun sight is based on the important characteristic of my optical unit 1 that the deflection of an aiming light ray passing through it varies with the decentration of the aiming light ray measured from the optical axis of the optical unit 1. This means that by the proper selection of the decentration it is possible to find an aiming light ray, in the plane defined by the vertical hair lines 6 and 16, which has a predetermined angle of deflection;

barrel 14 and as the aiming light rays entering the rear surface 3 of my optical unit-1 are also parallel to axes 4, and 14,'it will be possible with my device to find an;

aiming light ray; in the plane of the vertical. hair lines, 6 and 16, by the proper selectionof the decentration, which ray forms a predetermined angle, after deflection, with axis of the gun barrel 14.

The selection of thedecentration of the aiming light ray is accomplished by-the help ofthehorizontal hairlines of the optical unit 1 and of the cross hair panel 10. These hair lines ,are calibratedin the following manner: Let us assume thatthe effectivetarget rangeof the gun is from 50 ft. to 1150 ft. and, the curve of the trajectory is known. The first step is to determine the gravitational drop of ;the trajectory at 50 ft.-target distance. This gravitational drop divided by the target distance, gives the tangent of the'elevation of thegun barrel required, for 50.ft.',t arget distance.,, Thenext step ,is to calculate from the optical data of the optical unit 1 the decentra: tion at whichttheaiming light ray hasthe angle of deflection equal to the angle of elevation obtained for- 50 ft. The calculated decentration will give the location .of the calibratedhorizontaLhair line to be used,f or. 0 ft. target distance. By the same method the required decentration of the aiming lightray and of the corresponding horizontal hair line can be determined for 150 ft. and

also for oneor more intermediate target distances. Finally the horizontal hair lines are marked on the posterior surface of the optical unitat the above calculated decentrations, measured from the optical axis 4, as shown in Fig. 2, and then the corresponding horizontal hair lines are marked on the crosshair panel at the same calculated decentrations, as shown in Fig. 3.

Let us assume that in the example illustrated in the drawing the horizontal hair lines 7 and 17 correspond to the 50 ft. target distance, the horizontalhair lines 9 and 19 correspond to the 150 ft. target distance, and the lines 8 and 18 to an intermediate targetdistance. With this calibration of my gun sightthe aiming at a target distance of 50 ft. merelyconsists of holding the gun so that the target appears at the intersection of the hair lines s in the example illustrated in Fig. 4the opticalaxisA ,is parallel, to vthela xislof the i4: I t

thereby willbe able to per-.

calibrated hair lines, and

. form accurate vand. rapid aiming at fast a varying target distances.

Its to be understood that theform of my invention herein described and illustrated is only an example of the same and that various changes in the size, shape, and arrangement of. parts may. be resorted to, without departing from the ,spirit of my invention or the scope of the subjoined claims.

I claim:

1. A sighting device for a gun. having a barrel, comprising a. transparent optical unit having a convex spherical frontvsurface. and a concave'spherical rear surface, de-

; fining an opticalaxis, said unit beingdimensioned to have predetermined -'dioptric power so as to deflect the light ray at predetermined variable angles at corresponding variation of thedecentration of said ray from the said optical axis, said optical unit being'provided with a vertical hairline'pa'ssing through 'said optical axis and with horizontal hair lines located at various distances from said optical axis;a cross hair panel, disposed perpendicularlyto said optical axis adjacent to said concave rearsurfaceof the opticalunit, and being provided with avertical hairline passing'thr'ough said optical axis, and

with'horizontal hair"liries.located at the same distances, as the corresponding horizontal hair lines of the said optical unit, from saidoptical axis; a sight tube enclosing and firmly supporting said optical unit and said cross r hair panel, andbeing firmly secured to said barrel so as to maintain a p'ermanentangular and positional relation between said barrel,'o'ptical unit and cross hair panel.

- .2. A gun sight for mounting on the barrel of a gun, comprising; a transparent optical unit having convex I spherical front surface and concave spherical rear sur- 16 and17-of the crosshair panel 10, and the lines 6 face, with an .opticalaxis passing through .the center points of'said spherical surfaces, said optical unit being dimensioned so as to deflect the light ray at various predetermined angles when the decentrat'ion of said light ray, measured from saidoptical axis,-is varied correspondingly, the rear surface of the said optical unit being provided. with "aivertical hair line'passing through the said optical axis, and with horizontal hair lines located at various dece'ntrations-from said optical axis; a cross hair panel located adjacent .to said rear surface of the optical unit and being provided witha' vertical'h'air line passing through said optical axis, andwith horizontal: hair lines located at the samefdecentrations from said optical axis, as the corresponding horizontal hair lines of said optical unit; support means secured to said barrel, mechanically connecting the said.barrel, optical unit and cross hair panel in a permanent angular and positional relation.

No references cited. 

